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000
FXUS64 KSJT 210926
AFDSJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
426 AM CDT TUE MAY 21 2013

.TODAY AND TONIGHT...
THE MAIN CONCERN IN THE SHORT TERM IS WITH SEVERE WEATHER
POTENTIAL ACROSS OUR EASTERN COUNTIES THIS AFTERNOON AND EVENING.

A FAIRLY STRONG SHORTWAVE TROUGH /CURRENTLY OVER THE SOUTHERN
ROCKIES/ WILL MOVE EAST INTO THE SOUTHERN PLAINS AND NORTH TEXAS
TODAY. A SURFACE COLD FRONT WILL PUSH SOUTH ACROSS OUR NORTHWESTERN
COUNTIES THIS MORNING...AND THROUGH OUR CENTRAL AND SOUTHERN
COUNTIES THIS AFTERNOON. THIS FRONT SHOULD EXIT OUR SOUTHEASTERN
COUNTIES BY 7-8 PM THIS EVENING.

AS LIFT FROM THE APPROACHING SHORTWAVE TROUGH IMPINGES ON THE
AREA...SOME OF THE MODELS INDICATE CONVECTIVE DEVELOPMENT ACROSS
PARTS OF THE BIG COUNTRY LATER THIS MORNING ALONG AND BEHIND THE
COLD FRONT. HAVE ADDED 20-30 POPS ACROSS OUR NORTHEASTERN COUNTIES
THIS MORNING FOR THIS POSSIBILITY. WITH INCREASING VERTICAL SHEAR
AND STEEP MID-LEVEL LAPSE RATES...CANNOT RULE OUT THE POSSIBILITY OF
A FEW STRONG ELEVATED STORMS WITH HAIL THIS MORNING. THE MAIN
SEVERE WEATHER POTENTIAL...HOWEVER...IS THIS AFTERNOON AND EVENING
ACROSS OUR EASTERN COUNTIES...WHEN FAVORABLE COMBINATION OF VERTICAL
SHEAR AND INSTABILITY WILL BE SUPPORTIVE OF ORGANIZED SEVERE STORMS.
STORMS ARE EXPECTED TO DEVELOP ALONG THE SOUTHWARD-MOVING COLD
FRONT. COULD HAVE DISCRETE SUPERCELLS INITIALLY...BEFORE STORMS
ORGANIZE INTO A QUASI-LINEAR MCS. OUR HEARTLAND AND NORTHWEST HILL
COUNTRY COUNTIES LOOK TO BE ON THE SOUTHWEST END OF THE ANTICIPATED
QUASI-LINEAR MCS. CARRYING THE HIGHEST POPS ACROSS OUR HEARTLAND
AND NORTHWEST HILL COUNTRY COUNTIES.

THE DRYLINE HAS RETREATED WEST OF OUR FORECAST AREA. THE 00Z NAM
AND GFS BOUNDARY LAYER FIELDS SUGGEST THAT THE DRYLINE COULD MAKE
AN INTRUSION INTO THE WESTERN CONCHO VALLEY AND NORTHERN EDWARDS
PLATEAU THIS AFTERNOON BEFORE BEING OVERTAKEN BY THE COLD FRONT.
WITH LESS CLOUD COVER EXPECTED ACROSS THESE AREAS ALONG WITH A
THERMAL RIDGING PATTERN AT 850 MB...TEMPERATURES COULD WELL REACH
THE 90-95 DEGREE RANGE FOR HIGHS BEFORE THE COLD FRONT ARRIVES.
TEMPERATURES ARE EXPECTED TO BE APPRECIABLY COOLER ACROSS THE BIG
COUNTRY...WHERE THE COLD FRONT ARRIVES EARLIER IN THE DAY AND
WHERE GREATER CLOUD COVER SHOULD DEVELOP.

THUNDERSTORM ACTIVITY WILL END LATER THIS EVENING ACROSS OUR
FAR SOUTHEASTERN COUNTIES AS THE COLD FRONT CONTINUES TO MOVE
SOUTH. IN THE WAKE OF THE FRONTAL PASSAGE...NORTH WINDS WILL
DIMINISH AND BECOME LIGHT OVERNIGHT...AS WEAK SURFACE HIGH
PRESSURE SETTLES SOUTH INTO OUR AREA. WITH THIS SETUP TEMPERATURES
WILL BE COOLER TONIGHT...AND GOING WITH OVERNIGHT LOWS IN THE 60-65
DEGREE RANGE. WHILE THE GFS MOS LOOKS TOO AGGRESSIVE /AT THIS TIME/
WITH THE RADIATIONAL COOLING FOR TONIGHT...OUR FORECAST LOWS MAY
NEED TO BE TWEAKED DOWN FURTHER.

.WEDNESDAY THROUGH FRIDAY...
BOTH THE GFS AND THE ECMWF SHOW A SHORTWAVE RIDGE DEVELOPING IN
THE UPPER LEVELS ACROSS WEST CENTRAL TEXAS. BUT THEY ALSO SHOW
SHOWERS AND STORMS ALONG THE WESTERN EDGE ACROSS MUCH OF WEST
TEXAS...WITH THE STORMS TRYING TO MOVE EAST INTO PORTIONS OF WEST
CENTRAL TEXAS EACH EVENING. WILL KEEP THE SLIGHT CHANCE POPS IN
THE FORECAST AS IS FOR NOW.

.SATURDAY THROUGH TUESDAY...
UPPER LEVEL RIDGE INTENSIFIES AND BROADENS...LEAVING WEST CENTRAL
TEXAS IN A HOT AND DRY PATTERN. 850 MB WINDS REMAIN OUT OF THE
SOUTH AND SOUTHEAST...WHICH HELPS MITIGATES THE TEMPERATURES A FEW
DEGREES...BUT STILL LOOKING LIKE READINGS WELL INTO THE 90S FOR
MEMORIAL DAY.


&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  87  63  92  69  92 /  20  10  10  10  10
SAN ANGELO  93  64  94  70  94 /  20  10   5  10  10
JUNCTION  94  64  93  70  93 /  30  20   5   5  10

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

19/07/07